flash flood, Tsunami, landslide and earthquake give explaination?50 to 75words ?

  • A flash flood is the swift flooding of the low lying areas that are caused by extremely heavy rains, hurricanes or melting water from snow. Such floods may also occur with the collapse of structures like dams or speedy melting of ice.
  • Massive sea waves that are caused by tectonic activities are called tsunamis. Underwater earthquakes, volcanic eruptions, or explosions displace huge quantities of ocean water resulting in tsunami.
  • Ground movements that with large-scale erosions are called landslides. Landslide occurs due to variations in the slope stability and gravity. 
  • Earthquakes are the tremors caused in the Earth's crust due to seismic waves. In an earthquake, the ground trembles and develop fissures too. Earthquakes can cause landslides and volcanic eruptions.

  • 0

flash flood - Flash floods are short-term events, occurring

within 6 hours of the causative event (heavy rain, dambreak, levee failure, rapid, snowmelt and ice jams) andoften within 2 hours of the start of high intensityrainfall. A flash flood is characterized by a rapidstream rise with depths of water that can reach wellabove the banks of the creek. Flash flood damage andmost fatalities tend to occur in areas immediatelyadjacent to a stream or arroyo. Additionally, heavyrain falling on steep terrain can weaken soil and causemud slides, damaging homes, roads and property.Flash floods can be produced when slow moving ormultiple thunderstorms occur over the same area.When storms move faster, flash flooding is less likelysince the rain is distributed over a broader area.tsunami -A tsunami is a giant wave (or series of waves) created by an undersea earthquake, volcanic eruption or landslide.

Tsunamis are often called tidal waves, but this is not an accurate description because tides have little effect on giant tsunami waves.

Far out in the ocean, tsunami waves dont get very high, but they move very fast. In fact, the National Oceanic and Atmospheric Administration (NOAA) reports that tsunami waves can travel as fast as a jet plane.

As a tsunami gets closer to land and the ocean depth decreases, the speed of the tsunami wave slows down and the height of the tsunami wave increases dramatically—along with its potential for destruction.One thing is certain about tsunamis: they are unpredictable. Once a tsunami makes landfall, the waves can last from five to 15 minutes and do not follow a set pattern. NOAA warns that the first wave may not be the largest.

Not all undersea earthquakes or other seismic events create tsunamis, which is why tsunamis are difficult to predict.

landslide -A landslide is the movement of rock, debris or earth down a slope. They result from the failure of the materials which make up the hill slope and are driven by the force of gravity. Landslides are known also as landslips, slumps or slope failure.

Some of the most common types of landslide in Australia are earth slides, rock falls and debris flows. The movement of landslide material can vary from abrupt collapses to slow gradual slides and at rates which range from almost undetectable to extremely rapid. Sudden and rapid events are the most dangerous because of a lack of warning and the speed at which material can travel down the slope as well as the force of its resulting impact. Extremely slow landslides might move only millimetres or centimetres a year and can be active over many years. Although this type of landslide is not a threat to people they can cause considerable damage to property.

Landslides can be triggered by natural causes or by human activity. They range from a single boulder in a rock fall or topple to tens of millions of cubic metres of material in a debris flow.

earthquake -

  1. The definition of an earthquake is the release of sudden and extreme energy that is caused by shifting in the Earth's crust.

    Facts About Earthquakes
    • A seismometer is used to record and measure the strength of an earthquake.
    • The Mercalli scale is used to measure the earthquake. Anything seven or above is considered extremely dangerous.
    • Earthquakes usually occur along fault lines, or cracks that occur within the Earths crust.
    • Japan, New Zealand, Alaska are all located on one side of a horseshoe-shaped fault line called the "Ring of Fire" that circles the Pacific Ocean and is responsible for frequent earthquakes and frequently erupting volcanos.
    • The "Ring of Fire" zone was responsible for the devastating earthquakes in Indonesia in 2004, in New Zealand in early 2011 as well as a 9.0+ quake and a series of offshore earthquakes in Japan in early 2011 which also resulted in a tsunami.
    • The San Andreas Fault is a fault line discovered in 1895 that stretches about one thousand and three hundred kilometers through California in the United States, and through Baja California in Mexico.
    • The San Andreas fault has been the cause behind a number of significant earthquakes, such as the San Francisco Earthquake in 1906, and the Loma Prieta Earthquake in 1989.

    A shaking in San Francisco that measures 3.2 on the Richter scale is an example of an earthquake.

  • 0
What are you looking for?